Tinted contact lens and method for making same

ABSTRACT

A tinted contact lens for insertion into an eye comprises a contact lens substrate and an iris-simulating pattern on the lens substrate. The iris simulating pattern comprises at least four distinctly colored colorants. A method for making a tinted contact lens for insertion into an eye comprises providing a plate having a surface, and lasing the plate to form at least one depression in the surface of the plate. The depression is of a shape constituting an iris portion pattern. A fluent colorant is introduced into the depression. The colorant is then transferred from the depression to a lens substrate in a manner so that the colorant colors the lens substrate in a colorant pattern of substantially the same shape as the iris portion pattern of the depression.

BACKGROUND OF THE INVENTION

[0001] This invention relates to tinted contact lenses and methods ofmaking tinted contact lenses.

[0002] Tinted contact lenses are often used for cosmetic purposes tochange the apparent color of the wearer's irises. For example, a personwith brown or blue eyes but desiring to have green eyes may wear contactlenses having a greenish pattern thereon to mask the wearer's iriseswith the greenish pattern.

[0003] Conventionally, tinting of contact lenses is achieved by printinga colored pattern onto a lens substrate via a pad printing process. Itis to be understood that the term “tinted” is intended to encompasscolored patterns of translucent and/or opaque pigmentations. The padprinting process employs a generally flat steel plate also known as acliché. A pattern (or depression) is etched into the cliché by aphoto-etching process. In operation, ink placed in the pattern istransferred to the lens substrate by a printing pad. To achieve a tintedlens of multiple colors, different colored inks are placed into three orfewer different patterns and serially transferred to the lens substrateby printing pads.

[0004] A disadvantage associated with conventional methods of tintingcontact lens substrates is that such methods cannot achieve patterns ofhigh resolution. In other words, the printed pattern on the lenssubstrate does not have nearly the detail of a human iris. The inabilityto achieve patterns of high resolution also prevents use of more thanthree different patterns on a lens substrate. As such, an observerviewing the wearer's eyes from five feet away or closer may determinethat the wearer is wearing tinted lenses. Another disadvantage is theextensive labor needed to etch a pattern into the cliché. Typically,four to six “man-hours” are required to etch each pattern. Moreover, thepattern must generally be etched to precise depths so that the ink canbe transferred effectively. Etching to such precise depths is oftendifficult. In many intricate or detailed patterns, depth variances of3-5 microns may render the cliché useless. Another disadvantage is thatthe corrosive chemicals (e.g., ferric chloride and hydrochloric acid)used to etch the pattern in the cliché are hazardous both to workers andto the environment. Thus, enhanced care and cost are needed in using anddisposing of the chemicals.

SUMMARY OF THE INVENTION

[0005] Among the several objects and advantages of the present inventionmay be noted the provision of an improved method for tinting contactlens substrates; the provision of such a method of tinting a lenssubstrate in which the tinted lens substrate more closely resembles ahuman iris than does a tinted lens substrate made by conventionalmethods; the provision of a method of tinting a lens substrate to form atinted lens having a pattern of greater intricacy; the provision of animproved method of forming a pattern in a cliché; the provision of amethod of forming a precise, intricate pattern in a cliché; theprovision of such a method of forming such a pattern in a lesslabor-intensive manner; the provision of a method of forming a patternin a cliché without use of hazardous chemicals; and the provision of atinted contact lens having a lens substrate an colorant image printedthereon of greater resolution than images printed on prior art tintedcontact lenses.

[0006] In general, a method of the present invention for making a tintedcontact lens for insertion into an eye comprises providing a platehaving a surface, and lasing the plate to form at least one depressionin the surface of the plate. The depression is of a shape constitutingan iris portion pattern. A fluent colorant is introduced into thedepression. The colorant is then transferred from the depression to alens substrate in a manner so that the colorant colors the lenssubstrate in a colorant pattern of substantially the same shape as theiris portion pattern of the depression.

[0007] In another aspect of the present invention, a method of making atinted contact lens for insertion into an eye comprises digitizing animage of a human iris into a computer. The digitized image is separatedinto a plurality of digitized image portions, which are used to form aplurality of depressions in a plurality of cliché portions. Eachdepression is of a shape constituting an iris portion pattern. Fluentcolorants are introduced into the plurality of depressions. Thecolorants are transferred from the depressions to the lens substrate ina manner so that the colorants color the lens substrate in a pluralityof colorant patterns of substantially the same shape as the iris portionpatterns of the depressions. The colorant patterns combine with oneanother to color the lens substrate in a manner to simulate a humaniris.

[0008] In yet another aspect of the present invention, a tinted contactlens for insertion into an eye comprises a contact lens substrate and aniris-simulating pattern on the lens substrate. The iris simulatingpattern comprises at least four distinctly colored colorants.

[0009] Other objects and features will be in part apparent and in partpointed out herinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a top plan view of a tinted contact lens of the presentinvention having a contact lens substrate and an iris simulating designprinted on the substrate;

[0011]FIG. 2a is fragmented top plan view of a printing plate (cliché)portion having a first depression therein, the first depression being inthe shape of a first iris portion pattern to be printed onto a contactlens substrate to form a first portion of the iris simulating design ofFIG. 1;

[0012]FIG. 2b is fragmented top plan view of a cliché portion having asecond depression therein, the second depression being in the shape of asecond iris portion pattern to be printed onto a contact lens substrateto form a second portion of the iris simulating design of FIG. 1;

[0013]FIG. 2c is fragmented top plan view of a cliché portion having athird depression therein, the third depression being in the shape of athird iris portion pattern to be printed onto a contact lens substrateto form a third portion of the iris simulating design of FIG. 1;

[0014]FIG. 2d is fragmented top plan view of a cliché portion having afourth depression therein, the fourth depression being in the shape of afourth iris portion pattern to be printed onto a contact lens substrateto form a fourth portion of the iris simulating design of FIG. 1;

[0015]FIG. 3 is a flow chart showing the steps in forming the patternsof FIGS. 2a-d in the cliché portions;

[0016]FIG. 4a is a schematic, side elevational view of the clichéportion of FIG. 2a showing ink filling the first depression and a doctorblade passed over the cliché portion to remove excess ink;

[0017]FIG. 4b is a schematic, side elevational view of the clichéportion of FIG. 4a in which a pad-printing pad is pressed against thecliché portion to transfer the ink from the depression to the pad;

[0018]FIG. 4c is a schematic, side elevational view of the pad of FIG.4b aligned with a blank contact lens substrate;

[0019]FIG. 4d is a schematic, side elevational view similar to FIG. 4c,but showing the pad pressed against the contact lens substrate totransfer ink from the pad to the lens substrate; and

[0020]FIG. 4e is a schematic, side elevational view similar to FIG. 4d,but showing the pad removed from the lens substrate to reveal a patternprinted on the lens substrate.

[0021] Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] Referring now to the drawings and first more particularly to FIG.1, a tinted contact lens of the present invention is indicated in itsentirety by the reference numeral 20. The contact lens 20 comprises acontact lens substrate 22 and an iris-simulating design, generallyindicated at 24, on the lens substrate. The contact lens substrate 22 ispreferably a conventional clear contact lens. The lens substrate 22 maybe a corrective or non-corrective lens. The iris simulating design 24 isgenerally annular in shape and is sized to cover or enhance a wearer'siris. The iris simulating design 24 may be opaque to partially orcompletely mask the wearer's iris or may be at least somewhattranslucent so that some of the wearer's iris may show through thedesign. It is to be understood that the term “tinted” is intended toencompass both iris simulating designs of translucent and/or opaquepigmentations. Preferably, the iris-simulating design 24 ismulti-colored and is more preferably comprised of four or more separatecolors. A pad printing process is preferably used to print theiris-simulating design 24 on the lens substrate 22. As described ingreater detail below, four or more separate design portions (eachpreferably of a different color) are serially printed on the lenssubstrate 22 during the printing process. The design portions (colorantpatterns) combine to form the multi-colored iris-simulating pattern 44.

[0023] Generally speaking, two sub-processes are used for making thetinted contact lens 20. The first sub-process is formation of aplurality of depressions 32, 34, 36, 38 (FIGS. 2a-d) in one or moreprinting plates (clichés) 30. The second sub-process is using thecliché(s) 30 in a pad printing process to transfer ink (or some othersuitable fluent colorant) from the depressions to the lens substrate 22(FIG. 1). Preferably, the ink is of a type well known in the tintedcontact lens industry having binding properties enabling it to adhere tothe lens substrate via a polymerization process. The ink may be opaqueor translucent after being transferred to the lens substrate.

[0024] The first sub-process is generally indicated at 40 in theflow-chart of FIG. 3. In the first step, represented by box 42, an irisimage is digitized into a computer. Digitizing the iris image may beaccomplished by scanning a photograph or rendering of a human iris intothe computer, or by use of a digital camera, or by using appropriatesoftware to create an image by the computer itself. It is to beunderstood that the methods of digitizing an iris image mentioned hereinare merely exemplary, and other methods of digitizing an iris image maybe employed without departing from the scope of this invention. Thedigitized iris image may also comprise a hybrid image formed fromdifferent aspects of two or more iris images. The computer is preferablyany commercially available computer having a suitable processor such asan Intel Pentium-3® processor.

[0025] As represented by box 44, the colors of the digitized iris imageare separated into selectively distinctive layers by use of commerciallyavailable software, such as Adobe Illustrator® or Adobe PhotoShop®. Inpractice, the iris image is comprised of thousands of tiny coloredregions and the colors of the regions may encompass thousands ofdifferent colors. The iris image is preferably analyzed by a designerfor determining where color separations are to be made. Preferably theimage is separated into four, five, six, seven, eight, nine, ten,eleven, twelve, or more distinct color regions. Each color region ispreferably mapped via a raster-based image editor, such as AdobePhotoShop®. Each color region is then converted to grayscale and thenconverted to a halftone pattern (box 46). Each halftone pattern is thenpassed through a vector-based computer drawing program, such as AdobeIllustrator®. With the use of the drawing program, the halftone pattern(or digitized image portion) is adjusted and sized for export,preferably as an encapsulated postscript file, to a laser control unitof a suitable laser (indicated by box 48). Each digitized image portioncomprises the combination of all of the tiny regions of the digitizediris image assigned to one of the selected color ranges. Preferably, thelaser is a yttrium aluminum gamet (YAG) laser, such as an Electrox®Scriba II, commercially available from Electrox USA, Indianapolis, Ind.The laser control unit is preferably operated with suitable software,such as that commercially available from Electrox USA. The cliché 30(e.g., FIG. 2a) is then aligned with the YAG laser. Referring to box 50,the laser is then operated with appropriate aperture and power settingsto meet the pattern width and depth requirements suitable to form thedepressions 32, 34, 36, 38 in the portions of the cliché 30. Byadjusting the various power settings and/or incorporating multiplepasses to the patterns, an operator is able to use the laser to vaporizefinite layers of the plate conforming to the exact depression shapesdesired. Preferably, the laser is operated using baselines of 2kilohertz, aperture of 3.8 mm, yielding 5/1000 particle beam, power at70 watts, and speed frequency of 8 hits per second.

[0026] The laser forms each depression in an iris portion pattern tocorrespond to each digitized image portion. In other words, thedigitized image portions combine to represent the digitized iris image,and the iris portion patterns of the depressions combine to representthe iris image to be printed on the contact lens substrate. As discussedabove, FIGS. 2a-d show depressions 32, 34, 36, 38 formed in clichéportions. It is to be understood that the cliché portions may beportions of a single cliché or may be portions of multiple cliché's. Inother words, the depressions may all be formed in a single cliché 30 ormay each be in a separate cliché without departing from the scope ofthis invention.

[0027] Use of a laser to form a depression in a cliché has severaladvantages over forming a depression by photo etching. To begin with, adepression formed with a laser is capable of greater resolution than adepression formed with a photo etching process. In particular, theresolution capabilities with the laser process is more than 9 timesgreater than that of the photo etching process. The corrosive nature ofthe photo etching process applied at higher resolution tends tocompletely obscure and break down the pattern's definition. Theresolution limitation of the photo etching process creates barriers toachieve resolutions requiring increased color variations formulticolored contact lenses. By using a laser process to overcome thelimitations in pattern resolution, a broader range of blending colorsmay be employed to create a tinted contact lens that provides a morenatural appearance.

[0028] Another advantage of forming a depression with a laser ratherthan photo etching is elimination of the need to use toxic and hazardouschemicals, such as ferric nitrate, hydrochloric acid, and nitric acid.These chemicals increase chances of work related accidents or healthissues. These chemicals are also hazardous to the environment andrequire EPA regulatory compliance for removal and disposal. Also, theunpredictability inherent in the photo etching process makes itdifficult to produce depressions of desired depth. The desired depth ofa typical depression used in a pad printing process to tint a contactlens is 17-25 microns. Depth variances with a photo etching process aregenerally ±3-5 microns. If the photo etching process does not achievethe desired depth, the pattern rendered is useless; the plate must beresurfaced and relapped and the complete process repeated. Conversely,if the pattern achieves too much depth (which is the tendency in theindustry), the evaporation of the excess ink thinners/retardant andpolymers are released into the air, thereby decreasing air quality.

[0029] Use of the laser process also increases the speed in whichdepressions may be formed in the cliché. In particular, the laborrequired to prepare a typical pattern in the cliché via a photo etchingprocess is 3-6 man-hours. The labor to prepare such a pattern via thelaser method of the present invention is less than one man-hour. Thus,use of the laser process results in a depression of greater resolution,reduces health risks and decreases cost of manufacture.

[0030] The second sub-process (i.e., transfer of ink from a depressionin the cliché to the lens substrate 22) is schematically shown in FIGS.4a-e. In FIG. 4a, the cliché 30 is shown having a depression 32 floodedwith ink 60. A doctor blade 62 is swept across the cliché 30 to wipe theink 60 from the cliché in a manner so that the ink is in only thedepression. As shown in FIG. 4b, a conventional pad-printing pad 64 isaligned with the depression 32 and pressed against the cliché 30 to pickup the ink in the depression. The pad 64 is then brought intoregistration (FIG. 4c) with a contact lens substrate 22 held on a lensholder 66 and then pressed (FIG. 4d) against the lens substrate todeposit the ink on the substrate in a pattern which constitutes a firstdesign portion 70 of the iris simulating design (FIG. 1). The pad 64 isthen released from the lens substrate 22 and the ink is allowed to dry.The first design portion 70 printed on the lens substrate 22 in thismanner preferably has substantially the same shape as the pattern of thedepression 32. Although not shown, additional design portions are thenserially printed on the lens substrate 22 by transferring ink fromdepressions 34 (FIG. 2b), 36 (FIG. 2c), 38 (FIG. 2d) in substantiallythe same manner as transferred from depression 32. Preferably, differentink colors are used for each printing pattern. The design portions(colorant patterns) combine to form the multicolored iris-simulatingpattern 44.

[0031] Although the iris-simulating pattern 44 has been described asbeing formed by the combination of four different colorant patternsprinted on the contact lens substrate 22, it is to be understood thatmore or fewer colorant patterns may be combined to form aniris-simulating pattern (e.g, three, five, six, seven, eight, nine, ten,eleven, twelve, or more colorant patterns) without departing from thescope of this invention. Preferably, however, four to twelve colorantpatterns are printed on the lens substrate to form the iris simulatingpattern. Also preferably, each colorant pattern is a different color.

[0032] In view of the above, it will be seen that the several objects ofthe invention are achieved and other advantageous results attained.

[0033] As various changes could be made in the above constructions andmethods without departing from the scope of the invention, it isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:
 1. A method of making a tinted contact lens forinsertion into an eye comprising: providing a plate having a surface;lasing the plate to form at least one depression in the surface of theplate, the depression being of a shape constituting an iris portionpattern; introducing a fluent colorant into the depression; providing acontact lens substrate; transferring the colorant from the depression tothe lens substrate in a manner so that the colorant colors the lenssubstrate in a colorant pattern of substantially the same shape as theiris portion pattern of the depression.
 2. A method as set forth inclaim 1 wherein transferring the colorant from the depression to thelens substrate comprises transferring the colorant from the depressionto the lens substrate via a pad printing process.
 3. A method as setforth in claim 1 wherein transferring the colorant from the depressionto the lens substrate comprises: providing a pad; bringing the pad andplate into contact with one another in a manner to transfer the colorantfrom the depression of the plate to the pad; bringing the pad and lenssubstrate into contact with one another in a manner to transfer thecolorant from the pad to the lens substrate.
 4. A method as set forth inclaim 1 wherein the step of lasing the plate comprises lasing the platewith a YAG laser.
 5. A method as set forth in claim 1 wherein the stepof lasing the plate to form at least one depression in the surface ofthe plate comprises lasing the plate to form a plurality of depressionsin the surface of the plate, each depression being of a shapeconstituting an iris portion pattern.
 6. A method as set forth in claim5 wherein the step of introducing a fluent colorant into the depressioncomprises introducing a plurality of different fluent colorants into theplurality of depressions, and wherein the step of transferring thecolorant from the depression to the lens substrate comprisestransferring each colorant from its corresponding depression to the lenssubstrate.
 7. A method as set forth in claim 5 wherein the colorants areserially transferred from their corresponding depressions to the lenssubstrate to form a multi-colored printed iris image on the lenssubstrate.
 8. A method as set forth in claim 6 further comprising:digitizing an image of a human iris into a computer; separating thedigitized image into a plurality of digitized image portions; using theplurality of digitized image portions to determine the shape of the irisportion patterns; and wherein the step of using the plurality ofdigitized image portions to determine the shape of the iris portionpatterns precedes the step of lasing the plate to form a plurality ofdepressions.
 9. A method as set forth in claim 1 further comprising:digitizing an image of a human iris into a computer; using at least aportion of the digitized image to determine the shape of the irisportion pattern; and wherein the steps of digitizing and using at leastof portion of the digitized image precedes the step of lasing the plate.10. A method of making a tinted contact lens for insertion into an eyecomprising: digitizing an image of a human iris into a computer;separating the digitized image into a plurality of digitized imageportions; using the plurality of digitized image portions to form aplurality of depressions in a plurality of cliché portions, eachdepression being of a shape constituting an iris portion pattern;introducing fluent colorants into the plurality of depressions;providing a contact lens substrate; transferring the colorants from thedepressions to the lens substrate in a manner so that the colorantscolor the lens substrate in a plurality of colorant patterns ofsubstantially the same shape as the iris portion patterns of thedepressions, the colorant patterns combining with one another to colorthe lens substrate in a manner to simulate a human iris.
 11. A method asset forth in claim 10 wherein transferring the colorants from thedepressions to the lens substrate comprises: providing a plurality ofpads; bringing the pads and cliché portions into contact with oneanother in a manner to transfer the colorants from the depressions tothe pads; bringing the pads and lens substrate into contact with oneanother in a manner to transfer the colorants from the pads to the lenssubstrate.
 12. A method of making a tinted contact lens as set forth inclaim 10 wherein the digitized iris image includes a plurality ofdiscrete regions and wherein the step of separating the digitized irisimage into a plurality of digitized image portions comprises: selectinga plurality of color ranges; assigning each of the regions of thedigitized iris image as corresponding to one of the plurality of colorranges, each digitized image portion comprising the combination of allof the regions of the digitized iris image assigned to one of theselected color ranges.
 13. A method of making a tinted contact lens asset forth in claim 10 wherein the step of using the plurality ofdigitized image portions to form a plurality of depressions in aplurality of cliché portions includes forming the plurality ofdepressions by lasing the cliché portions.
 14. A method as set forth inclaim 13 wherein the step of lasing the cliché portions comprises lasingthe cliché portions with a YAG laser.
 15. A method as set forth in claim13 wherein transferring the colorants from the depressions to the lenssubstrate comprises transferring the colorants from the depressions tothe lens substrate via a pad printing process.
 16. A method as set forthin claim 10 wherein separating the digitized image into a plurality ofdigitized image portions comprises separating the digitized image intoat least four digitized image portions, and wherein the step of usingthe plurality of digitized image portions to form a plurality ofdepressions comprises using the plurality of digitized image portions toform at least four digitized image portions.
 17. A method as set forthin claim 10 wherein separating the digitized image into a plurality ofdigitized image portions comprises separating the digitized image intoat least five digitized image portions, and wherein the step of usingthe plurality of digitized image portions to form a plurality ofdepressions comprises using the plurality of digitized image portions toform at least five digitized image portions.
 18. A method as set forthin claim 10 wherein separating the digitized image into a plurality ofdigitized image portions comprises separating the digitized image intoat least six digitized image portions, and wherein the step of using theplurality of digitized image portions to form a plurality of depressionscomprises using the plurality of digitized image portions to form atleast six digitized image portions.
 19. A method as set forth in claim10 wherein separating the digitized image into a plurality of digitizedimage portions comprises separating the digitized image into at leastseven digitized image portions, and wherein the step of using theplurality of digitized image portions to form a plurality of depressionscomprises using the plurality of digitized image portions to form atleast seven digitized image portions.
 20. A method as set forth in claim10 wherein separating the digitized image into a plurality of digitizedimage portions comprises separating the digitized image into at leasteight digitized image portions, and wherein the step of using theplurality of digitized image portions to form a plurality of depressionscomprises using the plurality of digitized image portions to form atleast eight digitized image portions.
 21. A tinted contact lens forinsertion into an eye, the contact lens comprising a contact lenssubstrate and an iris-simulating pattern on the lens substrate, the irissimulating pattern comprising at least four distinctly coloredcolorants.
 22. A tinted contact lens as set forth in claim 21 whereinthe iris simulating pattern comprises at least four colorant patternsprinted on the contact lens substrate, each colorant pattern being of adistinct colorant.
 23. A tinted contact lens as set forth in claim 22wherein each colorant is an ink.
 24. A tinted contact lens as set forthin claim 23 wherein each ink is opaque.